DS2740

2 of 15

Table 1. ORDERING INFORMATION

PART

MARKING

PIN-PACKAGE

DS2740U

DS2740

15-Bit Current Resolution,

mMAX

DS2740U/T&R

DS2740

15-Bit Current Resolution,

mMAX, Tape-and-Reel

DS2740BU

DS2740B

13-Bit Current Resolution,

mMAX

DS2740BU/T&R

DS2740B

13-Bit Current Resolution,

mMAX, Tape-and-Reel

DESCRIPTION

The DS2740 provides high-precision current-flow measurement data to support battery-capacity

monitoring in cost-sensitive applications. Current is measured bidirectionally over a dynamic range of 15

bits (DS2740U) or 13 bits (DS2740UB), with the net flow accumulated in a separate 16-bit register.

Through its 1-Wire interface, the DS2740 allows the host system read/write access to status and current

measurement registers. Each device has a unique factory-programmed 64-bit net address that allows it to

be individually addressed by the host system, supporting multibattery slot operation. The interface can be

operated with standard or overdrive timing.

Although the DS2740 is primarily intended for location on the host system, it is also suited for mounting

in the battery pack. The DS2740 and FuelPack™ algorithms, along with host measurements of

temperature and voltage, form a complete and accurate solution for estimating remaining capacity.

Figure 1. BLOCK DIAGRAM

1-WIRE

INTERFACE

AND

ADDRESS

DQ

PIO

TIMEBASE

CURRENT

ACCUMULATED

CURRENT

STATUS/CONTROL

CHIP

GROUND

SNS

IS2

IS1

15-Bit + Sign

ADC

R

IS

10 k

W

R

IS

10 k

W

FuelPack is a trademark of Dallas Semiconductor.